When Sophie Lieberman ’21 returned to Yale after October recess, she realized an unexpected visitor had entered her suite. In her bedroom on the sixth floor of Saybrook, she found mouse droppings scattered on top of and under her desk — right beside her bed.

Lieberman had already seen two mice in her suite before leaving for fall break. But she is not the only student who has found a new furry friend in a dorm room this year. Current residents of Saybrook, Branford and Davenport Colleges all reported spotting mice on multiple occasions in their suites. Mice have also been spotted in the dining halls of Trumbull, Saybrook and Branford this year, as well as Bass Library, Lanman-Wright Hall, Jonathan Edwards and Pierson, according to 23 students interviewed by the News.

“It’s really bothersome, but I’m not super motivated to do something about it,” Lieberman said. “It’s an old building and [mice] are everywhere in the city.”

Yale Facilities tried to fix her problem. Lieberman’s suite had already been treated for mice two weeks before she saw the mouse droppings. Still, the exterminators did not leave any mouse traps and did not ask where mice had been spotted in the suite, according to Lieberman. Only a note was left stating that the exterminators had visited, and the suite had been “treated.”

Since the beginning of the year, Lieberman has spotted mice three times in her suite and four times in the Saybrook dining hall, where students are permitted to study outside of dining hours.

In a statement to the News, Yale spokeswoman Karen Peart said that whenever an issue in the residential colleges requires attention from facilities, the issue is “quickly and efficiently addressed.”

“If there is an issue with mice, we will immediately conduct inspections and treat areas if needed,” Peart said.

Kodi Scott, facilities superintendent for Saybrook and Trumbull, and Monica Gallegos, superintendent for Berkeley and Hopper, declined to comment for this story. Facilities superintendent for Silliman and Timothy Dwight Melissa Debies-Carl said she did not know of or have any mice issues in her area. Facilities superintendents for the other colleges and Director of Facilities and Grounds Mark McCloud did not respond to requests for comment.

In Branford, residents of five suites said they have seen mice in their rooms this year. Daniel Lee ’21, a student in JE who was annexed to Branford this year, said a mouse bit through the side pocket of his backpack last month. Lee said his suitemates did not call facilities to complain, but, after nibbling through his backpack “a little more,” the mouse eventually left his suite. However, Lee said he can still hear mice in the walls next to his bed.

Vy Tran ’21 said her suite in Branford has dealt with a “colony” of mice — this year, they have spotted mice five times, most recently Thursday night. Tran said they put in a facility request two weeks ago, and a note was placed on their door stating that maintenance had come for the mouse and advised them to “wait several days.” Tran’s suitemate also found a “poison box” in the suite after requesting a facilities order.

According to Tran, the first mouse looked like a baby, and the rodents have gotten progressively bigger since then. Tran speculated that the first baby mouse has either gotten “exponentially bigger from eating our goods” or multiple mice have visited the suite.

Branford Head of College Enrique De La Cruz said he was unaware of a mice issue in the college.

“In the fall it is not uncommon for mice to enter buildings to escape the cold,” De La Cruz said in an email to the News. “If someone sees a mouse in the building, I would hope that they call Facilities right away so that the problem can be addressed.”

According to three Saybrook residents, mice are often seen darting through the dining hall in the evenings. Two students said they have seen mice in the Trumbull dining hall at night, and two Branford residents said they have spotted mice in their dining hall. Associate Vice President for Yale Hospitality Rafi Taherian did not respond to request for comment.

While many students have encountered unwelcome visitors to their rooms and dining halls, not all were concerned by the presence of the small critters. Many have not reported the issue to Yale Facilities.

Saybrook resident Lauren Delgado ’21 said she saw a mouse in her suite last week and caught it with her suitemates before releasing it onto Old Campus. And Akhil Rajan ’21, who lives in Branford, said he has seen a mouse twice in his suite and set up a mouse trap.

“I named it Mac,” Rajan said. “If I find another, I shall name it cheese.”

Rajan added that while the mice problem is “not ideal,” he called it is a relatively minor problem “in the grand scheme of things.”

“There are obviously a lot of important things that Yale should invest resources into, but this seems like a pretty easy fix,” Rajan said. “Of course, I’m sure the age of the building is a complicating factor, so maybe it’s not that easy!”

On Tuesday night, Raymond Zhao ’22 posted a video of a mouse scurrying through Bass Library in the popular Facebook group “Overheard at Yale.” The video’s caption read “there’s a MOUSE in the library, I’m suing.”

Still, Zhao said he was not that worried about mice in Yale facilities.

“Honestly, it was kind of cute, but I do worry about the cleanliness of the facility,” Zhao said. “I’d be more worried if I saw it in a dining hall where my food is being prepared.”

Tran, the Branford resident who has seen mice five times, said that while she is not personally concerned, some of her suitemates are “scared that the mice get into our stuff and carry diseases.”

According to Jamie Childs, a lecturer in the Yale School of Public Health’s Department of Epidemiology of Microbial Diseases, the mice found in residential colleges are most likely house mice, which are less likely to carry infectious diseases than wild mice. While house mice are still associated with “a number of zoonotic pathogens” — diseases transferred between animals and humans — Childs said many of these pathogens are “very rarely disseminated.”

Childs advised students and Yale Facilities to pay greater attention to sanitation procedures during this “time of a mouse plague,” but added that he was certain Yale had already undertaken these measures to handle mice. Mice commonly enter buildings when the weather gets colder as they seek out “somewhere warm and nice during the winter,” Childs added.

Still, mice do not pose a large risk to humans unless they leave droppings around food, said Andrew Rizzo, former executive director of the New Haven Livable City Initiative.

“Mice are always going to be around,” Rizzo said. “Yale has the wherewithal to address these issues. It depends on where their priorities are.”

The problem of mice is not new to many students and faculty. Lee, whose backpack was bitten through by a mouse this year, said a mouse also ate through his sister’s backpack last year in his JE suite.

Berkeley Head of College David Evans wrote in an email that Berkeley has had some “additional little residents” in the past, but he is not aware of any major issues with mice this year. TD Head of College Mary Lui said her college has not had any mice problems as far she knows. And Benjamin Franklin Head Charles Bailyn said he has not heard of any rodent problems, possibly due to Franklin’s recent construction.

Bailyn added that “the beasties may well find a way in over time.”

The cost of room for the 2018-2019 academic year is $9,000.

Alice Park | alice.park@yale.edu